Planet Names

From Alderaan to Gallifrey to Vulcan, the fictional universe is populated with lots of planets with beautiful or interesting names. Who wouldn't like to visit Divine Wind -- or avoid Hell?

In the real universe, though, astronomers have a lot of work to do when it comes to naming planets. HD 13931 b sounds about as appealing as a tax audit.

Of course, we know very little about the worlds outside our own solar system, so there isn't a pressing need for better names -- not yet, anyway.

Astronomers designate an extrasolar planet with the name of its star followed by a letter, starting with "b." The letters are bestowed based on the order of discovery, not a planet's location within the system. In the system 55 Cancri, for example, the planets line up e, b, c, f, and d.

A few stars with known planets have names based on their constellations, but most simply have catalog numbers. That's where we get names like MOA-2008-BLG-310-L b -- a planet discovered by the Microlensing Observations in Astrophysics project, in 2008, in the central bulge of the Milky Way galaxy.

One bright star with a known planet and an easy name is in good view tonight. Fomalhaut is low in the southeast at nightfall, and due south around midnight. It's in a barren patch of sky, so it's easy to pick out. Hubble Space Telescope has taken a picture of its planet -- a tiny, faint dot known -- of course -- as Fomalhaut b.

Script by Damond Benningfield, Copyright 2010

For more skywatching tips, astronomy news, and much more, read StarDate magazine.

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